#include<iostream>
#include<string>
#include<vector>
using namespace std;

class Solution {
public:
    int numWays(int n) {
        if(n==0){
            return 1;
        }
        if(n<=2){
            return n;
        }
        int a = 1;
        int b = 2;
        int sum = 0;
        while(n>=3){
            sum = (a+b)%t;
            a = b;
            b = sum;
            --n;
        }
        return sum;

    }
public:
    long long t = 1000000007;
};

int main(){
    Solution S;
    cout<<S.numWays(7)<<endl;
}